The effect of temperature and diet on the energy flow in immature octopuses Enteroctopus dofleini was investigated. The energy used in respiration, voided in waste and consumed and stored in somatic tissue by captive immature octopuses was monitored. The results suggest that a mixed low lipid diet of approximately 3% body weight provided every 3 days, and temperatures of between 7-9.5°C lead to the largest amount of energy being available for growth and activity. The efficiency of different temperatures and diets are discussed in terms of importance to aquaculture and implications on the behaviour of immature E. dofleini in the field.